Vinyl floors or floor coverings, the composition of which is particularly based on a polyvinyl chloride (PVC) lining, are well-known today as replacements for linoleum coverings due to their impermeability, resistance to abrasion, and chemical agents, as well as their non-slip and easy-to-clean properties. Therefore, such lining is extremely suitable for high-traffic areas that require frequent cleaning, such as kitchen, bathroom or children's playroom floors.
In addition to being characterized by their composition, vinyl linings are characterized by being provided with a decorative layer imitating typical linings ranging from those that look like wood, granite or ceramic, to others having more cutting-edge designs that can be obtained by printing any design with different drawings, patterns and colors.
These vinyl linings are found on the market mainly in two formats, i.e., in the form of tiles or boards and in the form of continuous rolls. Linings in tile format are more useful if a part experiences any deterioration because it is only necessary to replace the tile in question and not the entire sheet of the roll.
With respect to placement, vinyl linings in the form of a tile require the application of a dispersion adhesive, gum or glue on the surface to be placed in contact with the floor, although for some time now tiles sold on the market have a self-adhesive layer protected by a sheet of paper that can be peeled off for direct application on the surface of the floor covering or floor to be covered. Vinyl tiles with a perimetral anchoring system for being installed directly on a subfloor can also be found on the market. Such tiles can be installed in a floating manner, i.e., simply connecting the parts to one another without having to adhere them to the surface.
It must be pointed out that vinyl linings have the drawback of having very poor dimensional stability because heat and temperature changes greatly affect them. Therefore, in adverse conditions of heat exposure, a vinyl tile will experience an expansion effect of up to 0.15% with respect to its initial size at room temperature of ±23° C. It can also bow and deform, losing its initial planimetry and therefore becoming detached from its support, or it can become disconnected from adjacent parts in the case of a floating installation. Vinyl linings are therefore unsuitable for floor coverings in installations where there are marked temperature changes (≧15° C.). Cold temperatures also significantly affect the dimensional stability of vinyl, being able to experience a shrinkage effect of more than 0.2% with respect to its initial size at room temperature of ±23° C. Generally, any installation having vinyl floors, particularly those installed in a floating system, must remain at a constant temperature of between 15° C. and 25° C.
To prevent stability problems caused by heat, there are mixed or composite vinyl linings in which the vinyl material is attached directly to a rigid or semi-rigid main layer or substrate having a certain constant thickness, such as cement or fiberglass-reinforced cement, known as fibrocement, thus forming a multilayer lining plate. Fibrocement has an excellent dimensional stability that remains unchanged in response to humidity or temperature changes, and the dimensional stability of fibrocement is ten times higher than the stability of vinyl material.
Nevertheless, the introduction of rigid or semi-rigid materials in the multilayer panel complicates and even prevents being able to actually connect the panels to one another since it is impossible to make any type of male-female groove on the edges of the panels without breaking a portion of the panel. Therefore, the panels either have no grooves and are arranged independently from one another, without acting as a uniform whole, or a groove must be molded together with the fibrocement layer, which makes the lining panel manufacturing process more expensive and longer since it is necessary to arrange molds for the grooves and to manufacture the main layer of the panel by pouring the fibrocement and waiting for it to set, without being able to use prefabricated fibrocement plates for that purpose.
Another added drawback of such multilayer plates is that the rigid or semi-rigid main fibrocement layer has caused difficulties in placing the multilayer lining plate on floors since ductility of the vinyl tile has been lost due to the attachment thereof to the rigid fibrocement layer.
Therefore, vinyl tiles could be easily applied on floor coverings or floors even though their finish is not completely smooth since vinyl is a ductile material that adapts to the imperfections or irregularities that the surface to be lined may have. Nevertheless, by having attached the fibrocement support layer, the resulting panel can hardly adapt to said irregularities and produces a “smacking” effect, a type of noise and certain vertical movement that occur when walking on the panel since the plate is usually only supported by three of its four corners, and upon stepping on the other corner, the plate moves as if it were a lever.
This effect means that floor coverings or floors should not be lined with mixed vinyl and fibrocement plates if they are not completely level and if they have no type of irregularity, which is very hard to find.
Leveling a floor and making sure that its surface is smooth and completely planar involves work and considerable implementation time that is hard to take on, counteracting the placement advantages linked to a vinyl material. Furthermore, in most cases in which the vinyl lining projects from a pre-existing, generally tiled, floor, it is common to find some edges or corners of tiles protruding with respect to adjacent tiles, whereby the lining with a mixed vinyl and fibrocement plate such as those described would only further increase the effect of irregularities due the difference in level, causing a disastrous result from both the aesthetic viewpoint and the personal safety viewpoint.
Based on the foregoing, it would be desirable to have a multilayer lining plate that is dimensionally stable under temperature and humidity conditions, that can be connected with adjacent plates so that the lining acts as a whole, and that is optionally capable of adapting to horizontal surfaces even though these surfaces do not have a perfectly horizontal and smooth finish free of irregularities.